chore: complete OOTB QA audit

Fixes identified during the thorough distro review:
- Restore automatic wallpaper switching by removing image filters from deployed themes.
- Fix broken 'Style' menu entries by creating missing about.txt and screensaver.txt branding files.
- Clean up conflicting keybindings by removing deprecated tiling.conf and updating doc generator.
- Remove legacy Nord theme hack from nomarchy-theme-set.
- Fix JSON parse error in summer-day waybar theme.

features/desktop/waybar/themes/summer-day/config.jsonc

@@ -29,7 +29,7 @@
           "8": [],
           "9": [],
           "10": []
-      },
+      }
   },
   
   "custom/launcher": {
@@ -79,7 +79,7 @@
           "default": ["", "", ""]
       },
       "on-click-right": "pavucontrol",
-    "on-click": "pactl set-sink-mute @DEFAULT_SINK@ toggle",
+    "on-click": "pactl set-sink-mute @DEFAULT_SINK@ toggle"
   },
 
 "network": {